Tube which empties completely

ABSTRACT

The invention concerns a packaging tube for pasty product, comprising a tubular skirt extending along an axial direction and sealed by swaging at the end of the tube, and a head located at the other end of the tube, the head including a dispensing passage and a neck forming a radial extension of the dispensing passage, the neck being connected to the skirt by a connecting surface. The skirt and the connecting surface have, respectively, a circumference and a radius of curvature such that the ratio of the circumference over the radius is not more than 20.

FIELD OF THE INVENTION

The present invention relates generally to packages in tube form, whichare traditionally used for the packaging of pasty products such asdentifrice, pharmaceutical products, creams and various cosmetologyproducts, food products, glues, mastics, etc.

BACKGROUND

A general problem encountered in ordinary use of tubes lies in the factthat it is impossible to empty them completely of their contents,resulting in a loss of packaged product, with unavoidable negativeeffects from both the economic and the ecological standpoints.

A tube is diagrammatically described in the patent document DE-2914370in order to solve this problem.

Although the solution proposed by this patent, which consists ofreducing the angle between the neck and the axis of the tube, is bothuseful and relatively effective, the adjustment of the parameterconstituted by this angle does not enable one to solve the problemmentioned above in all the cases in point, that is to say with tubes ofvarious sizes, consisting of different materials and enclosing productsof various viscosities.

Furthermore, known, for example, through patent documents WO 96/30272and FR 2 105 590 are flexible tubular bottles which, although they haveconsiderable variations of thickness according to a transversedirection, aim to solve the same problem.

In reality, these containers not only pose relatively intensemanufacturing problems but they are also found to be subject to anunsolvable compromise between the risk of air tightness failure of thezones of lesser thickness, with the need, in order to avoid this risk,to increase the extra thickness of the zones of greater thickness, andthe industrial need to produce tubes with a minimum of material.

SUMMARY OF THE INVENTION

The invention is situated in this context and proposes a tube whichempties completely, making it possible to palliate the limitations andproblems mentioned above.

The invention more precisely relates to a packaging tube which has: atubular skirt elongated in an axial direction, the skirt having afilling end closed off by collapsing of the skirt in a transversedirection and forming a first end of the tube; and a head situated at asecond end of the tube, away from the filling end, the head having achannel for distribution of the pasty product and a neck in the form ofa radial extension of the distribution channel, the neck being connectedto the skirt by a connecting surface, the connecting surface having, ina longitudinal plane containing the axial direction and perpendicular tothe transverse direction, a particular minimum radius, and the skirthaving, in a plane transverse to the axial direction and situated midwaybetween the ends of the tube, a particular circumference and a roughlyconstant thickness.

For this purpose, the tube of the invention is characterized by the factthat the ratio of the particular circumference to the minimum radius isless than twenty (that is to say less than 6π) and preferably at mostequal to ten (that is to say barely over 3π).

Furthermore, with respect to the axial direction, the neck preferablyhas a maximum inclination less than 60 degrees.

In practice, it can prove useful to give the connecting surface, withrespect to the axial direction, a maximum inclination of, at most, 45degrees or even, at most, equal to 30 degrees.

In order to make the tube of the invention even easier to use, it ismoreover possible to make the ratio of the average thickness of the neckto the average thickness of the skirt at most equal to 2.

According to a preferred embodiment, the skirt and the head are producedin the form of a single piece, without a connecting zone.

In the case corresponding to a preferred application of the invention,and in which the tube is produced by injection of a thermoplasticmaterial and must be made air tight in order to ensure the protection ofits contents, this tube is preferably covered on its whole surface,including the head, with a protective varnish called a “barriervarnish,” for example, deposited by spraying.

Contrary to the prior art, in which the tube skirts are obtained byextrusion, it is possible in the invention to define the skirt by agenerating line not parallel to the axial direction of the tube.

Finally, the ease of use of the tube of the invention is furtherimproved by choosing, for the skirt and the head, an elasticallyextendible material having very satisfactory flexibility.

BRIEF DESCRIPTION OF THE DRAWINGS

Other characteristics and advantages of the invention will emergeclearly from the description given hereafter in an indicative and in noway limiting basis in reference to the appended drawings in which

FIG. 1 is a front view of a known packaging tube, shown before use;

FIG. 2 is a front view of a known packaging tube, shown after use;

FIG. 3 is a front view of a packaging tube according to a firstembodiment of the invention, shown before use;

FIG. 4 is a front view of a packaging tube according to a firstembodiment of the invention, shown after use;

FIG. 5 is a front view of a packaging tube according to a secondembodiment of the invention, shown before use;

FIG. 6 is a front view of a packaging tube according to a thirdembodiment of the invention, shown before use; and

FIG. 7 is a perspective view of the packaging tube illustrated in FIG.6.

DETAILED DESCRIPTION

As shown by all the figures, the invention relates generally to apackaging tube for a pasty product, which essentially has tubular skirt1 and head 2.

In a preferred embodiment, head 2 and skirt 1 are produced in the formof a single piece, with no connecting zone.

The skirt has an elongated shape along an axial direction XX′ and ends,including a filling end 121 which, after injection of the product whichis to be packaged, is closed off by collapsing of this skirt 1, possiblywith heat, along a transverse direction ZZ′.

Head 2, which is situated at end 122 of the tube away from filling end121, has a distribution channel 3 for the packaged product, and a neck 4in the form of radial extension of channel 3 and which is connected toskirt 1 by a connecting surface 5.

The problem encountered in emptying the tubes of prior art at the end ofuse is illustrated in FIGS. 1 and 2 and lies in the fact that it isimpossible to collapse the head in order to make the product remainingthere come out of it.

In order to limit the loss of product generated by the packaging in theform of a tube, the solution traditionally adopted in the prior artconsists of reducing the volume of the product which cannot be expelledfrom the tube at the end of use.

Thus, the most conventional known approach has always led to providingthe greatest slope of neck 4 and of connecting surface 5 to make anangle A, with respect to the axial direction XX′, which corresponds tothe greatest possible inclination and, in all cases, equals 60 degrees.

The present invention, which like document DE-2914370 proceeds inexactly the opposite manner and which seeks not to reduce the lostvolume of packaged product but rather to avoid any loss of product, onthe contrary, recommends preferably making the neck 4 have, with respectto the axial direction XX′, a maximum inclination A of less than 60degrees.

Depending on the material used for producing the tube and on thethickness of the head, it is even preferable to give the connectingsurface 5, with respect to the axial direction XX′, a maximuminclination B which is, at most, equal to 45 degrees, and, evenpossibly, at most, equal to 30 degrees.

But in any case, the invention provides associating with these preferredcharacteristics a particular choice of parameters relating to thegeneral shape of the tube, making it possible to use materials withvarious deformation capabilities for the manufacturing of the tube.

The first parameter to be taken into consideration is the smallestradius R5 of connecting surface 5 in the longitudinal plane L1 whichcontains the axial direction XX′ and which is perpendicular to thetransverse direction ZZ′.

The second parameter to be taken into consideration is the circumferenceC1 of the skirt in a transverse plane T perpendicular to the axialdirection XX′ and situated midway between ends 121, 122 of the tube.

Hypothetically, skirt 1 furthermore has, in any transverse planeparallel to plane T, a local thickness which is both roughly constantand equal to or very close to equal to the average thickness E2 of thisskirt over its whole length along axis XX′.

According to its fundamental aspect, the invention thus provides givingthe ratio C1/R5 of circumference C1 to the minimum radius R5 a valueless than 20 (that is to say less than 6π), preferably, at most equal toten (that is to say barely over 3π), and most preferably, not largerthan 1.5.

According to another aspect of the invention, the ease of pressing atthe end of use of the tube can be improved by giving skirt 1 and neck 4identical or very similar average thicknesses, or at least by giving theratio of the average thickness of the neck to the average thickness ofthe skirt a value at most equal to 2.

Inasmuch as the thickness of the tube according to the invention,particularly at the site of the neck, must be rather small in order toensure great flexibility of the head and can consequently becomeinsufficient to ensure the tightness of the tube with regard to air,and, more particularly, the oxygen contained in the air, and to preservethe contents of the tube, it is preferable to cover the tube with abarrier varnish over its whole external surface including head 2;distribution channel 3 can, however, be free of this coating inasmuch asit can have a greater thickness with no problem.

However, since the tube according to the invention can assume arelatively complex shape, which can furthermore aim for a particularaesthetic result, it is preferable to deposit this barrier varnish byspraying, and not by use of a roller as is generally done in prior art.

The invention applies preferably to the production of tubes whose skirt1 and head 2 are formed in a single piece by injection of athermoplastic material which has an elastic extension capability in itsplane of at least five percent, preferably, and, possibly, more than tenpercent.

As shown in FIG. 6, the skirt can then be defined by a generating line Gnot parallel to the axial direction XX′, thus, there is more freedom asto the shape of the tube than in the prior art.

What is claimed is:
 1. A packaging tube for a pasty product, thepackaging tube including: a tubular skirt elongated along a central axisof the packaging tube, and having a filling end closed by collapsing ofthe tubular skirt in a transverse direction and forming a first end ofthe packaging tube; a head at a second end of the packaging tube, remotefrom the first end, and having a distribution channel for the pastyproduct and a neck as a radial extension of the distribution channel;and a connecting surface connecting the neck to the tubular skirt, theconnecting surfaced having, in plane including the central axis, aradius of curvature transverse to the central axis, and the skirthaving, in a plane transverse to the central axis and situated midwaybetween the first and second ends of the packaging tube, a circumferenceand a generally constant thickness, wherein a ratio of the circumferenceto the radius of curvature is no more than twenty.
 2. The packaging tubeaccording to claim 1, wherein the ratio of the circumference to theradius is no more than ten.
 3. The packaging tube according to claim 1,wherein, with respect to the central axis, the neck has a maximuminclination of less than 60 degrees.
 4. The packaging tube according toclaim 1, wherein the connecting surface has, with respect to the centralaxis, a maximum inclination of 45 degrees.
 5. The packaging tubeaccording to claim 4, wherein the connecting surface has, with respectto the central axis, a maximum inclination of 30 degrees.
 6. Thepackaging tube according to claim 1, wherein the tubular skirt and theneck have respective first and second average thicknesses and a ratio ofthe second average thickness to the first average thickness is, at most,equal to two.
 7. The packaging tube according to claim 1, wherein thetubular skirt and the head are a thermoplastic material.
 8. Thepackaging tube according to claim 1, including a barrier varnishcovering the packaging tube, including the head.
 9. The packaging tubeaccording to claim 1, wherein the skirt is defined by a generating linenot parallel to the central axis.
 10. The packaging tube according toclaim 1, wherein the skirt and the head are an elastically extendiblematerial.
 11. The packaging tube according to claim 1, wherein thetubular skirt and the head are a single piece.
 12. The packaging tubeaccording to claim 1, wherein the ratio does not exceed 1.5.